cp_parser_attributes_opt doesn't accept GNU attributes followed by
[[]] attributes and vice versa; only a sequence of attributes of the
same kind. That causes grief for code like:
struct __attribute__ ((may_alias)) alignas (2) struct S { };
or
#define EXPORT __attribute__((visibility("default")))
struct [[nodiscard]] EXPORT F { };
It doesn't seem to a documented restriction, so this patch fixes the
problem.
However, the patch does not touch the C FE. The C FE doesn't have
a counterpart to C++'s cp_parser_attributes_opt -- it only has
c_parser_transaction_attributes (which parses both GNU and [[]]
attributes), but that's TM-specific. The C FE seems to use either
c_parser_gnu_attributes or c_parser_std_attribute_specifier_sequence.
As a consequence, this works:
[[maybe_unused]] __attribute__((deprecated)) void f2 ();
but this doesn't:
__attribute__((deprecated)) [[maybe_unused]] void f1 ();
I'm not sure what, if anything, should be done about this.
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
PR c++/102399
PR c++/69585
gcc/cp/ChangeLog:
* parser.cc (cp_parser_attributes_opt): Accept GNU attributes
followed by [[]] attributes and vice versa.
gcc/testsuite/ChangeLog:
* g++.dg/ext/attrib65.C: New test.
* g++.dg/ext/attrib66.C: New test.
* g++.dg/ext/attrib67.C: New test.
---
gcc/cp/parser.cc | 14 +++++++++++---
gcc/testsuite/g++.dg/ext/attrib65.C | 7 +++++++
gcc/testsuite/g++.dg/ext/attrib66.C | 27 +++++++++++++++++++++++++++
gcc/testsuite/g++.dg/ext/attrib67.C | 27 +++++++++++++++++++++++++++
4 files changed, 72 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/ext/attrib65.C
create mode 100644 gcc/testsuite/g++.dg/ext/attrib66.C
create mode 100644 gcc/testsuite/g++.dg/ext/attrib67.C
diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index 3fc73442da5..535bf7eedbb 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -28727,9 +28727,17 @@ cp_nth_tokens_can_be_attribute_p (cp_parser *parser,
size_t n)
static tree
cp_parser_attributes_opt (cp_parser *parser)
{
- if (cp_next_tokens_can_be_gnu_attribute_p (parser))
- return cp_parser_gnu_attributes_opt (parser);
- return cp_parser_std_attribute_spec_seq (parser);
+ tree attrs = NULL_TREE;
+ while (true)
+ {
+ if (cp_next_tokens_can_be_gnu_attribute_p (parser))
+ attrs = attr_chainon (attrs, cp_parser_gnu_attributes_opt (parser));
+ else if (cp_next_tokens_can_be_std_attribute_p (parser))
+ attrs = attr_chainon (attrs, cp_parser_std_attribute_spec_seq (parser));
+ else
+ break;
+ }
+ return attrs;
}
/* Parse an (optional) series of attributes.
diff --git a/gcc/testsuite/g++.dg/ext/attrib65.C
b/gcc/testsuite/g++.dg/ext/attrib65.C
new file mode 100644
index 00000000000..0af138700f6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/attrib65.C
@@ -0,0 +1,7 @@
+// PR c++/102399
+// { dg-do compile { target c++11 } }
+// Test mixing the GNU and standard forms of attributes.
+
+#define EXPORT __attribute__((visibility("default")))
+
+struct [[nodiscard]] EXPORT Foo { Foo(); };
diff --git a/gcc/testsuite/g++.dg/ext/attrib66.C
b/gcc/testsuite/g++.dg/ext/attrib66.C
new file mode 100644
index 00000000000..102ed709b1d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/attrib66.C
@@ -0,0 +1,27 @@
+// PR c++/69585
+// { dg-do compile { target c++11 } }
+
+struct __attribute__ ((aligned (2))) __attribute__ ((may_alias))
+S1 { };
+
+struct __attribute__ ((aligned (2))) [[gnu::may_alias]]
+S2 { };
+
+struct alignas (2) __attribute__ ((may_alias))
+S3 { };
+
+struct alignas (2) [[gnu::may_alias]]
+S4 { };
+
+
+struct __attribute__ ((may_alias)) __attribute__ ((aligned (2)))
+S1_2 { };
+
+struct [[gnu::may_alias]] __attribute__ ((aligned (2)))
+S2_2 { };
+
+struct __attribute__ ((may_alias)) alignas (2)
+S3_2 { };
+
+struct [[gnu::may_alias]] alignas (2)
+S4_2 { };
diff --git a/gcc/testsuite/g++.dg/ext/attrib67.C
b/gcc/testsuite/g++.dg/ext/attrib67.C
new file mode 100644
index 00000000000..a5107665077
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/attrib67.C
@@ -0,0 +1,27 @@
+// PR c++/69585
+// { dg-do compile { target c++11 } }
+// Test mixing the GNU and standard forms of attributes.
+
+__attribute__((deprecated)) [[maybe_unused]] void f1 ();
+[[maybe_unused]] __attribute__((deprecated)) void f2 ();
+[[maybe_unused]] __attribute__((deprecated)) [[nodiscard]] int f3 ();
+__attribute__((unused)) [[nodiscard]] __attribute__((deprecated)) int f4 ();
+
+struct [[maybe_unused]] __attribute__((aligned)) S1 { double d; };
+struct __attribute__((aligned)) [[maybe_unused]] S2 { double d; };
+
+enum E {
+ X [[maybe_unused]] __attribute__((unavailable)),
+ Y __attribute__((unavailable)) [[maybe_unused]],
+};
+
+void
+g ([[maybe_unused]] __attribute__((unavailable)) int i1,
+ __attribute__((unavailable)) [[maybe_unused]] int i2)
+{
+ [[maybe_unused]] __attribute__((aligned)) int i3;
+ __attribute__((aligned)) [[maybe_unused]] int i4;
+
+[[maybe_unused]]
+lab: __attribute__((cold));
+}
base-commit: 891d64721626f45fb95fa47a57a3f396b80f31e9
--
2.36.1
